Abstract
Purpose :
Anterior chamber angle morphology in the Ugandan population has not been previously described. We aim to study the anatomy of the anterior chamber angle quantitatively by ultrasound biomicroscopy (UBM) in healthy eyes of patients attending the eye clinic at Mulago Hospital in Kampala, Uganda.
Methods :
A cross-sectional observational study was performed, involving 33 patients who attended the general eye clinic at Mulago Hospital in April 2016. Parameters measured on UBM included; the angle opening distance (AOD) at 500µm from the scleral spur, iris thickness (ID1), trabecular-ciliary process distance (TCPD), iris ciliary process distance (ICPD), iris zonule distance (IZD) and trabecular iris angle (TIA). Other parameters assessed included; Snellen visual acuity (VA), intraocular pressure (IOP), central corneal thickness (CCT), spherical equivalent (SE) and whether they had an underlying diagnosis of diabetes mellitus. Patients with primary open angle glaucoma or pre-existing anterior segment pathology were excluded.
Results :
A total of 31 eyes from 31 patients were eligible for inclusion. Of these 19 were female and 12 were male. The average age of patients was 47 years. All eyes had dark brown iridies. 25 eyes had VA 6/9 or better. The mean CCT was 531.29µm and the mean IOP was 15.74mmHg. Average measurements for angle morphology with UBM were as follows; AOD 0.46mm (95% CI 0.41-0.59), ID1 0.57mm (95% CI 0.54-0.65), TCPD 1.20mm (95% CI 1.16-1.30), ICPD 0.24mm (95% CI 0.22-0.30), IZD 0.77mm (95% CI 0.74-0.86) and TIA 30.31 degrees (95% CI 28.34-35.91). No statistically significant correlation was identified between the anterior chamber angle (TIA or AOD) and the following parameters: IOP, CCT, SE, ID1 or an underlying diagnosis of diabetes mellitus.
Conclusions :
No patients within our study were identified to have occludable angles. When compared to published studies looking at similar angle morphology in populations including Caucasian and Asian eyes, the trabecular iris angle was on average wider and the iris thicker in the Ugandan cohort. Our findings suggest that angle closure glaucoma may be less prevalent within the Ugandan population. However, further studies are required to support our conclusions.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.